Lost in Translation: An Antiviral Plant Defense Mechanism Revealed Valérie Nicaise  Cell Host & Microbe  Volume 17, Issue 4, Pages 417-419 (April 2015) DOI: 10.1016/j.chom.2015.03.009 Copyright © 2015 Elsevier Inc. Terms and Conditions

Figure 1 Model of NIK1-Mediated Defense in Plants After virus particles enter into plant cells, the ssDNA (single-stranded DNA) circular genome is released (1) and becomes double stranded during the replication step (2). The dsDNA (double-stranded DNA) is transcribed into mRNAs (3) that are subsequently integrated into the host translational machinery for viral protein synthesis (4). Unknown virus infection-associated signal(s) trigger(s) NIK1 homodimerization, and transphosphorylation of the kinase domain at threonine 474 (T474), leading to NIK1 kinase activation (5). Activated NIK1 phosphorylates the cytoplasmic protein RPL10 (6), leading to RPL10 translocation into the nucleus (7), where it binds the transcription factor LIMYB (8). The LIMYB-RPL10 transcriptional complex blocks the expression of ribosomal protein genes (9), which impacts host cell protein translation negatively and consequently blocks the synthesis of viral proteins (10). As a countermeasure, the viral protein NSP blocks NIK1 functions by interacting with its kinase domain, thus restoring viral protein translation (11). Cell Host & Microbe 2015 17, 417-419DOI: (10.1016/j.chom.2015.03.009) Copyright © 2015 Elsevier Inc. Terms and Conditions